Frank Farrelly is the author of a book called Provocative Therapy focusing on radical therapeutic moves intended to jolt the client out of his current mindset. This approach was modeled by Richard Bandler during the early years of Neuro-Linguistic Programming.

Provocative therapy was developed in an inpatient ward as Farrelly, dissatisfied with his effectiveness as a therapist, and influenced by Carl Rogers and Spurgeon English, began to explore new procedures for promoting significant, resilient change in chronic and recalcitrant patients. He worked in this institutional setting for 17 years, continuing to develop and refine his techniques.

In the late 1970s the Temple University Psychiatric Department held a conference, Analysing the Analyst, where Farrelly gave a number of demonstrations of his work. It was during this period that Richard Bandler and John Grinder began to take an interest in his ideas. Many who have observed both Bandler and Farrelly believe that Provocative Therapy has had a significant influence on the development of the NLP approaches and attitudes.

Farrelly holds a Master's Degree in Social Work from Catholic University and is a member of the Academy of Certified Social Workers. For many years he was a clinical professor at the University of Wisconsin School of Social Work and an assistant clinical professor in the Department of Psychiatry at the University of Wisconsin Medical School.

Farrelly has been described by one of his clients as "The kindest, most understanding man I have ever met in my whole life, wrapped up in the biggest son of a bitch I have ever met."

Along with the book Provocative Therapy and numerous articles, Farrelly (in collaboration with Nick Kemp) recorded the cd Me and God - a humorous autobiographical account of his life and work. Farrelly was born into an Irish-American family as the ninth of twelve children. During his workshops he often references his childhood experiences and how these were a key influence on his work.